The Feuds of the Clans, by Alexander MacGregor, , at sacred-texts.com
About the year of God 1438, there fell some variance betwixt the Keiths and some others of the inhabitants of Caithness. The Keiths, mistrusting their own forces, sent to Angus Mackay of Strathnaver (the son of Neil Wasse), entreating him to come to their aid, whereunto he easily yielded; so Angus Mackay, accompanied with John Mor MacIan-Riabhaich, went into Caithness with a band of men, and invaded that country. Then did the inhabitants of Caithness assemble in all haste, and met the Strathnaver men and the Keiths at a place in Caithness called Blair-tannie. There ensued a cruel fight, with slaughter on either side. In the end the Keiths had the victory, by the means chiefly of John Mor MacIan-Riabhaich (an Assynt man), who was very famous in these countries for his manhood shown at this conflict. Two chieftains and leaders of the inhabitants of Caithness were slain, with divers others. This Angus Mackay, here mentioned, was afterwards burnt and killed in the Church of
[paragraph continues] Tarbat, by a man of the surname of Ross, whom he had often molested with incursions and invasions.